Previously, when `setModel` was called, we forgot to update the pointer
to the component in the newly supplied editor. This was causing the
element to not update in response to model updates but only as a result
of focus or visibility changes. We suspect this regressed during the
rewrite of the editor rendering layer.
With this commit we will now correctly swap the element's underlying
editor by updating the component pointer on the newly supplied editor.
Also, if the element was already attached to another editor, we will
null out the component reference on it, because one instance of
`TextEditorElement` can only represent one instance of `TextEditor`.
Previously, we were mistakenly not clearing out some styling properties
like `marginTop`, thus causing e.g. line numbers to be misaligned. This
was caused by manual updates to an element's style object, without a
consequent update to the NodePool.
With this commit we will now rely on `element.styleMap` (a DOM
primitive) to detect which styles have been set on a element that is
about to be recycled and, if the object being created doesn't use them,
simply clear them out.
Before rendering block decorations, we read their heights by putting
them into a special div called `blockDecorationMeasurementsArea`.
Previously, this div was not explicitly sized, which was causing
decorations to wrap while being measured but not when actually rendering
them.
This commit fixes this inconsistency by explicitly styling the
measurement area so that it has the same width as the component scroll
width.
By the time that the animation frame is delivered, the requested
autoscroll
position could not exist anymore. This could cause the editor component
to measure a non-existent line and, as a result, throw an exception.
With this commit we will always ignore measurements for screen lines
that do not exist.
This means we may render more tiles than necessary when we have block
decorations, but it prevents changing the number of rendered tiles
during scrolling with certain combinations of line height and editor
height. If it ever becomes a problem we can get smarter about
subtracting the height of the visible block decorations from the editor
height, but for now this gives us more reliable performance for the
common case.
Previously, we were accidentally depending on the state of the display
layer when forcing it to update its index. This caused us to not index
enough content to cover the visibile area, which meant we weren't
querying enough lines to fill the screen in some situations.
This was causing problems in measurements because in that code path we
assume that text nodes are never empty. This commit also adds a test
verifying this invariant when a text decoration ending right after a
text tag is added.
This was leaving a measurement request in the map that was getting
picked up on the next frame. In some cases, the requested measurement
row was not present, causing an exception.
